Severe emphysema is a debilitating disease that limits quality of life of patients and represents an end state of Chronic Obstructive Pulmonary Disease (COPD). It is believed that 3.5 million people in the US have the severe emphysematous form of COPD, and it is increasing in both prevalence and mortality. Current treatment methods for severe emphysema include lung volume reduction (LVR) surgery, which is highly invasive, and can be risky and uncomfortable for the patient. New treatment methods for treating emphysema include bronchoscopy guided lung volume reduction devices that aim to close off ventilation to the diseased regions of the lung, but maintain ventilation to healthier lung. Bronchoscopy-guided techniques have the promise to be less invasive, less costly and more highly accurate treatments for patients with severe disease and improve the quality of life of severe emphysema patients.
Emphysema can present itself in various disease forms (i.e., phenotypes). Predicting the right treatment for these patients at the appropriate time in the disease process may depend on the phenotype of the disease. Imaging techniques provide an in-vivo mechanism to objectively quantify and characterize disease phenotype and can be used as the patient selection process for the various procedural options. Quantitative imaging biomarkers can be used to effectively phenotype disease and therefore predict those patients most likely to respond to the targeted treatment options. By triaging the right patient to the appropriate therapy, there exists a greater promise for a positive impact on patient outcome, reduced healthcare costs, and replacing more invasive procedures like LVR surgery in treating patients with severe emphysema.
Bronchoscopic procedures such as the placement of pulmonary valves, coils, and the use of bio-sealants and energy delivery for lung volume reduction can provide effective ways of treating emphysema by shrinking over-inflated portions of the lungs. However, because of the complexity of lung anatomy and the diversity of disease among individuals, planning for such procedures can be difficult. For example, it can be difficult to determine which locations are best suited for the placement of valves and whether how such locations can be best accessed bronchoscopically. Difficulties can therefore arise after such a treatment is already in progress, such as difficulties in accessing the location for placement of the valve or delivery of the bio-sealant or energy, or the results of such treatment may be less effective than anticipated due to disease aspects that might not have been appreciated before the procedures such as fissure integrity and the presence of collateral ventilation.
Another lung disease, lung cancer, is the world's leading cause of cancer death, causing more annual deaths (about 28% of all cancer deaths) than any other cancers for which there are routing screening programs such as breast, colorectal, and prostate. Lung cancer comprises about 14% of cancer diagnoses each year, including smokers as well as non-smokers. Only about 15% of lung cancer cases are diagnosed at an early stage while 85% are diagnoses at a late stage. As with all cancers, early detection of lung cancer is critical to patient outcome. However, the five-year survival rate for lung cancer is only about 16%, and over half of patients die within the first year of diagnosis. The five-year survival rate for lung cancer is much lower than that of many other leading cancers, but this could be improved through improved early detection.
One method of screening for lung cancer uses low-dose computed tomography (CT), which resulted in a 20% reduction in lung cancer mortality in one trail. The U.S. Preventive Services Task Force has recommended annual screening for lung cancer using low-dose CT for adults aged 55 to 80 years old who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years, due to the increased risk for lung cancer in this population. However, several publications have shown an association between radiographic emphysema and airflow obstruction and lung cancer, confirming the presence of emphysema or airflow obstruction in most middle-aged to older long-term smokers and ex-smokers with proven lung cancer. Therefore, while the criteria currently employed for selecting patients for low-dose CT lung cancer screening are useful, other factors may also be useful and a more refined selection process could make lung cancer screening more cost effective.